Once you’re there, open the file called “hosts”. If you
don’t see anything listed just type the word hosts and the
file should open up. Just the word “hosts”, no extension or
anything after that. It’s probably blank but it might not
be.

Add this line:

127.0.0.1 pagead2.googlesyndication.com

And save. You’re done.

Now go back to a site that you know has some Google Ads.
There should be an empty space where the ads appeared.

Want to turn it off? Don’t just delete it, put a “#” sign in
front of that line, like this which is equivalent to commenting the statement:

# 127.0.0.1 pagead2.googlesyndication.com

What’s that do? It basically says “ignore this line.” I like
to leave it like that so when I want to hide Google Ads
again, all I have to do is remove the “#” sign and save –
then put the “#” back in when I’m ready to go back to
normal.

To me, making a quick change in your HOSTS file to turn
AdSense on and off is easier than fiddling around with a
firewall program.